I am carrying out a dynamic mesh model of a piston damper, when the damper enters its pocket there is a very small radial clearance, 0.12mm. the diameter of the damper is approximately 80mm. I want to set up the model so that while the model is clear of the pocket the mesh is fairly coarse but as the damper enters the pocket the mesh is very fine in the annular section and around the inlet and outlet to this annulus. Can anyone point me in the right direction as to how to set up the mesh and dynamic mesh parameters for this problem

I am also trying a similar case for dynamic mesh. what i got feedback from fluent is that you must have some gap between the two faces if in operation, they touch each other. fluent automatically merges and collapses the control volumes based on specified criteria. please browse through the help for daynamic mesh feature of fluent.